I have a new app server that is running Server 2012 R2 on-site. The image was provided by a vendor... For some reason, although SMB1/2/3 are (well, should be anyhow...) enabled, it always wants to connect to other servers on SMB 1.01... I have 2 other Server 2012 R2 computers. I can on the other servers with the powershell cmdlet "get-smbsession | Fl *" that the app server is connecting with "1.01" dialect. How can I "tell the app server" to use the latest SMB but allow it to keep using SMB1 if it has to connect to old servers, etc...

If I run a get-smbserverconfiguration on the app server in question, here is what I get:

Myke, why would the other Server 2012 R2's be able to use SMB 3 when connecting to each other? Why is it that this newly introduced Server 2012 R2 needs the parameter added??? The new image is not default... I can see it is definitely highly customized by the vendor. Perhaps they changed something?

Shouldn't Server 2012 R2 be able to use SMB3 by default, when connecting to other R2 systems? (From a fresh install of Server?)

Little Green Man, I already made sure SMB3 is enabled... This is the article I followed before. I used the powershell command to make sure it was on and manually added the SMB1 and SMB2 DWORDs to the Lanmanserver Parameters registry key. I also rebooted the server after that, and still it wants to use SMB 1.01??????

How to enable or disable SMB protocols on the SMB client (from M$ article)

That is correct. A system that doesn't have the protocol enabled certainly cannot talk in that protocol and will revert to what it does have available. 3.0 is backwards compatible, but 1.1 is not forward compatible.

I will say, its odd that they disabled SMB 3... I think they might have disabled it while we were testing because of issues. It looks like on Server 2012 R2, by default, mrxsmb20 is enabled/running... Thanks again!

I will say, its odd that they disabled SMB 3... I think they might have disabled it while we were testing because of issues. It looks like on Server 2012 R2, by default, mrxsmb20 is enabled/running... Thanks again!

That actually was done on purpose due to the very issue you just witnessed.